Search results for "laser"
showing 10 items of 3161 documents
WHISPERING GALLERY MODE SILICA MICROSPHERE RESONATOR APPLICATIONS FOR BIOSENSING AND OPTICAL FREQUENCY COMBS
2021
Čukstošās galerijas modu rezonatori (ČGMR) ir piesaistījuši interesi savu optisko īpašību un daudzveidīgo pielietojumu dēļ. ČGMR virsma tika pārklāt ar vairākiem funkcionalizējošiem slāņiem. Tika izstrādāts un pielāgots glikozes sensora modelis. Lai nodrošinātu selektivitāti, tika izmantota glikozes oksidāze (GOx), un, lai uzlabotu sesnsora jutību, - zelta (Au) nanodaļiņas (NP). Tika pārbaudītas vairākas ZnO nanostruktūras, lai palielinātu virsmas laukumu un proteīnu pieķeršanos, kas bija selektīvas govju leikēmijas vīrusa antigēna/antivielu reakcijām. Frekvences ķemmes, kas ģenerētas ČGMR (WCombs), var izmantot datu pārraidei. WComb ierosināšanai tika izmantoti pumpēšanas lāzeri C-joslas t…
Calcium Carbonate and Phosphate Reference Materials for Monitoring Bulk and Microanalytical Determination of Sr Isotopes
2017
In situ laser ablation analyses rely on the microanalytical homogeneity of reference materials (RMs) and a similar matrix and mass fraction between unknown samples and RMs to obtain reliable results. Suitable carbonate and phosphate RMs for determination of Sr isotope ratios in such materials are limited. Thus, we determined Sr-87/Sr-86 ratios of several carbonate (JCt-1, JCp-1, MACS-1, MACS-3) and phosphate (MAPS-4, MAPS-5, NIST SRM 1400, NIST SRM 1486) international RMs using dissolved samples and two different multi-collector inductively coupled plasma-mass spectrometers (MC-ICP-MS). Our Sr isotope data are in agreement with published data and have an improved measurement precision for s…
Reliability and Intersession Agreement of Microperimetric and Fixation Measurements Obtained with a New Microperimeter in Normal Eyes.
2015
Purpose: To evaluate the reliability and intersession agreement of measurements of retinal sensitivity as well as of the fixation pattern obtained in healthy eyes with a microperimeter integrating the mechanism of the scanning laser ophthalmoscope (SLO) with the static perimetry. Methods: This study included a sample of 44 healthy eyes of 44 subjects of a mean age of 27.0 ± 8.5 years. In all cases, microperimetric exams with the MAIA system (Centervue, Padova, Italy) were performed in three different sessions to evaluate the intersession repeatability. The consistency of measurements was analyzed by using the Friedman test and by analyzing the correlation between consecutive measurements. A…
A laser desorption/resonance enhanced photoionisation TOF-system for the spatially resolved trace analysis of elements
2004
Abstract A novel method for direct and spatially resolved elemental trace analysis with high sensitivity and elemental selectivity is presented. The concept is based on the combination of a commercial MALDI-TOF mass spectrometer with a pulsed laser system for resonant postionisation of neutrals. While the MALDI method is usually applied for investigations of large organic compounds and biomolecules, the technique discussed here concerns the low mass range around 1 ⩽ A ⩽ 300. The analytical performances of the setup with respect to mass analysis, spatial resolution and overall detection efficiency are discussed.
Comparison of two methods skipping cell lysis and protein extraction for identification of bacteria from blood cultures by matrix-assisted laser deso…
2019
ABSTRACT Objective Matrix-assisted laser desorption/ionization time-of-flight mass-spectrometry (MALDI-TOF MS) is widely used for fast identification of bacteria from blood cultures (BC). We compared the performance of two procedures, one including a pre-enrichment step in brain heart infusion and the other a direct method using vacutainer separator gel tubes (DI), for identification of bacteria from blood cultures by MALDI-TOF MS. Material and methods We first prepared a training set of 20 simulated bacteremia specimens, including 10 Gram-negative and 10 Gram-positive species. A total of 145 non-consecutive BCs flagged as positive (68 Gram-negative rods, and 77 Gram-positive cocci) were pr…
MALDI-TOF mass spectrometry identification of filamentous fungi in the clinical laboratory.
2014
Pôle MERS F. Dalle; International audience; This study aimed to validate the effectiveness of a standardised procedure for the MALDI-TOF mass spectrometry (MS)-based identification on a large sample of filamentous fungi routinely identified in university hospitals' laboratories. Non-dermatophyte filamentous fungi prospectively isolated in the routine activity of five teaching hospitals in France were first identified by conventional methods in each laboratory and then by MS in one centre. DNA sequence-based identification resolved discrepancies between both methods. In this study, of the 625 analysed filamentous fungi of 58 species, 501 (80%) and 556 (89%) were correctly identified by conve…
A Multicentre Pilot Study of a Two-Tier Newborn Sickle Cell Disease Screening Procedure with a First Tier Based on a Fully Automated MALDI-TOF MS Pla…
2019
The reference methods used for sickle cell disease (SCD) screening usually include two analytical steps: a first tier for differentiating haemoglobin S (HbS) heterozygotes, HbS homozygotes and β-thalassemia from other samples, and a confirmatory second tier. Here, we evaluated a first-tier approach based on a fully automated matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF MS) platform with automated sample processing, a laboratory information management system and NeoSickle® software for automatic data interpretation. A total of 6701 samples (with high proportions of phenotypes homozygous (FS) or heterozygous (FAS) for the inherited genes for sickle h…
In situobservation of the generation and annealing kinetics of E ′ centres induced in amorphous SiO2by 4.7 eV laser irradiation
2011
The kinetics of E' centers induced in silica by 4.7eV laser irradiation was investigated observing in situ their optical absorption band at 5.8 eV. After exposure the defects decay due to reaction with diffusing molecular hydrogen of radiolytic origin. Hydrogen-related annealing is active also during exposure and competes with the photo-induced generation of the centers until a saturation is reached. The concentrations of E' and H2 at saturation are proportional, so indicating that the UV-induced generation processes of the two species are correlated. These results are consistent with a model in which E' and hydrogen are generated from a common precursor Si-H.
RILIEVO IN MODALITÀ DINAMICA DEL PARCO NINNI CASSARÀ A PALERMO E SVILUPPO DI UN APPLICATIVO PER LA GESTIONE DELLA MANUTENZIONE
2014
Nel corso degli anni le tecniche di monitoraggio hanno sviluppato una tendenza esponenziale verso la semplificazione e la velocizzazione, sia delle operazioni di rilievo, che di restituzione e analisi dei dati rilevati giungendo nel contempo a livelli di accuratezza sempre più spinti. Questo volgere continuo al miglioramento delle prestazioni tecnologiche e all’ottimizzazione delle risorse in termini di tempo e denaro, per gli addetti ai lavori, ha posto la moderna Geomatica in linea con la mentalità propria del terzo millennio di fare meglio e più in fretta. Tra le tecnologie che sempre più stanno prendendo campo in quest’ottica si inserisce il Mobile Mapping System che su una qualunque pi…
Toward a wave turbulence formulation of statistical nonlinear optics
2012
International audience; During this last decade, several remarkable phenomena inherent to the nonlinear propagation of incoherent optical waves have been reported in the literature. This article is aimed at providing a generalized wave turbulence kinetic formulation of random nonlinear waves governed by the nonlinear Schrodinger equation in the presence of a nonlocal or a noninstantaneous nonlinear response function. Depending on the amount of nonlocal (noninstantaneous) nonlinear interaction and the amount of inhomogeneous (nonstationary) statistics of the incoherent wave, different types of kinetic equations are obtained. In the spatial domain, when the incoherent wave exhibits fluctuatio…